Ring Elite Surface mounting/ Working in connection with Ring 2 and Original chime.

My intention is to install the Elite on a steel post that's part of a sliding powered front gate install BUT; Q1 It appears that ithe Elitet can only be mounted flush. Is this correct or is there a surface mount kit available Q2 The package comes with a 50' ethernet cable for connection to the POE supply. Can the cable be longer? My install location is probably 80 feet from Ethernet access on a router. Q3 I have an original Ring Chime. Will I be able to use this chime with the Elite. Q4 Can I use the Elite connected via Ethernet to my Wifi router to operate the chime as I do now using wifi.? Q5 I alo have a Ring 2 mounted next to the front door and operated via wifi. Will the Ring 2, Ring Elite, and Ring Chime all play happily together? Thanks in advance. Steve